JAMIA 2021 — Reasoning PYQ

Step 1: Calculate the first differences

Let's find the difference between each term and the one before it:

• $18-5=13$

• $34-18=16$

• $54-34=20$

• $79-54=25$

• $110-79=31$

• $158-110=48$

The sequence of first differences is: $13,16,20,25,31,48$.

Step 2: Calculate the second differences

Now, let's find the differences between these differences:

• $16-13=3$

• $20-16=4$

• $25-20=5$

• $31-25=6$

• $48-31=17$

Step 3: Identify the pattern

The second differences follow a clear arithmetic pattern: $3,4,5,6,\dots$.

Following this logic, the next second difference should be $7$ instead of $17$.

Step 4: Find the correct number

If the pattern is consistent, the last first difference should be:

Therefore, the last term in the series should be:

In the given series, the number provided is $158$.